Additional surface conductance of the weakly charged porous surface layer of a colloidal particle
Zharkikh N. I., Dukhin S. S.
Additional surface conductance is the excess of total surface conductance over the conductance of a diffuse electrical double layer. Theoretical estimation of this value is based on the notion of the porous layer of a colloidal particle. The charge of the porous layer is described by the Stern-Langmuir isotherm. Specific calculations have been made for the particular case of the low Donnan potential of the gel layer. It was established that interfacial potential difference is mostly localized in a medium (gel or solution) where screening is less effective. This fact is responsible for the possible appearance of a maximum at the concentration dependence of a ζ-potential. In this case, additional surface conductance exceeds Bikerman's conductance: the pattern of the concentration dependence in the first case is governed by the coverage of adsorption sites for potential-determining ions.
1. Dukhin, S.S. and Derjaguin, B.V., Surface and Colloid Science, Matijevic, E.M., Ed., New York: Wiley-Interscience, 1974, vol. 7, p. 356.
2. Dukhin, S.S., Adv. Colloid Interface Sei., 1993, vol. 44, p.l.
3. Bikerman, J., Trans. Faraday Soc, 1940, vol. 36, p. 154.
4. Schwarz, G., J. Phys. Chem., 1962, vol. 66, p. 2636.
5. Rosen, L.A., Baygents, J.C., and Saville, D.A., J. Chem. Phys., 1993, vol. 98, p. 4183.
6. Lyklema, J., J. Electroanal. Chem., 1968, vol. 18, p. 341.
7. Klein, J., Colloids Surf., 1990, vol. 51, p. 371.
8. Simonova, T.S. and Shilov, V.N., Kolloidn. Zh., 1986, vol. 48, no. 2, p. 370.
9. Dukhin, S.S., Shurts, Yu., and Pfiranger, Yu., Kolloidn. Zh., 1993, vol. 55, no. 6, p. 21.
10. Pastushenko, V., and Donath, E., Stud. Biophys., 1976, vol. 56, p. 7.
11. Donath, E. and Pastushenko, V., Bioelectrochem. Bioenerget., 1979, vol. 6, p. 343.
12. Ohshima, H., J. Colloid Interface Sci., 1994, vol. 162, p. 80.
13. Zharkikh, N.I., Pendze, Kh., and Dukhin, S.S., Colloid. J., 1994, vol. 56, no. 4.
14. Healy, T. and White, L., Adv. Colloid Interface Sei., 1978, vol. 9, p. 303.
15. Zhura, N.A., Ermakova, L.E., and Sidorova, M.P., Kolloidn. Zh., 1993, vol. 55, no. 5, p. 67.
16. Berezkin, V.V., Kiseleva, O.A., Nechaev, A.N., et al. Colloid. J., 1994, vol. 56, no. 3, p. 258.
17. Van der Stieg, H.G.M., De Reyser, A, Cohen Stuart, M.A., and Bijsterbosch, B.H., Colloid Surf., 1993, vol. 70, no. 1, p. 77; 1993, vol. 70, no. 1, p. 91.
Biocolloid chemistry institite, Academy of sciences of Ukraine, Kyiv
Received 14 Mar 1994
Published : Colloid Journal (Moscow), 1994, vol. 56, № 6, p. 755 – 760.
Full text in english languages.